Behavior: works via sensory pathway/nervous systems Behaviors have a genetic basis allows for evolution by natural selection Learning connects experience and behavior genetics x environment
Q1. What stimulus elicits the behavior, and what physiological mechanisms bring about the response? Q2. How does the animal’s experience during growth and development influence the response? Q3. How does the behavior aid survival and reproduction? Q4. What is the behavior’s evolutionary history? Take home message:
Q1: stimuli that trigger behavior Tinbergen kept fish tanks with stickleback fish Males = red belly; Females= no red belly Male territorial behavior related to red color males also behaved aggressively when a red truck passed by! Fixed Action Pattern: developmentally ‘fixed’ → innate behavior trigger = sign stimulus (i.e. red color)
Environmental stimuli trigger and guide animal behaviors for innate and learned behaviors Birds, fishes, mammals (+ more) use cues to migrate long distances Why do animals not get lost in new habitats? Animals may use sun or moon position to navigate adjust route with circadian clocks!
Animal behaviors also reflect biological rhythms (Q1) circadian clocks or longer cycles Migration and reproduction cued by seasonal cycles periods of day length and darkness Behaviors rhythms related to lunar cycles includes tides (e.g. crab reproduction, turtle nesting)
Stimulus may come from other animals (Q1) Signal: male waving claw at female crab Communication: transmission and reception of signals plays a role in primary cause (‘the How’) 4 common modes of animal communication visual, chemical, tactile & auditory
Step 1: Male sees female and orients towards her uses olfactory chemical system to determine species Step 2: Male touches female with foreleg alerts female to his presence Step 3: Male vibrate wing in courtship song auditory behaviors tells female he is of right species If all communications are successful → sexy time
Many terrestrial mammals are nocturnal use olfactory and auditory forms usually are color blind Humans and most birds are diurnal use visual and auditory forms lack many olfactory cues The amount of information communicated is variable read Honey Bee dance language in book
Q2: How does the animal’s experience during growth and development influence behavior? What behaviors are innate and what are learned? cross-fostering & human twin studies
Learning: Learning capacity → nervous system organization during development genome encoded (behavvior exists) finches can sing, but learn song from father Both nature (genes) vs nurture (environment) Learning Types: Imprinting, Spatial, Associative, Cognitive, Social
Q3: How does the behavior aid survival and reproduction? Food related behaviors: eating, searching, recognizing & capture how did foraging behavior evolve? Fruit flies: variation in an foraging gene (for) dictates larva travel when foraging forR (rover) vs forS (sitter) Which allele will be selected for in a population?
Mate choice and mating behavior influence reproductive success Seeking, attracting & choosing mates mate competition Evolution of parental care produces more viable offspring monogamy vs polygamy certainty of paternity Mate choice behavior leads to sexual and intrasexual selection
Behaviors have a genetic basis Courtship fruit fly: series of behaviors in male flies single gene (flu) controls entire ritual if flu mutated → no mating can be reversed in male and female!!! variation in gene → variation in behavior Variation in environment may cause behavior to evolve
Behaviors should be mostly selfish individual vs competitors Altruism: sterile male bees animals that vocalize warning calls Can unselfishness arise through natural selection? offspring survival: yours and relatives Inclusive fitness: increases genetic representation of related offspring